1. Technical Field
The present invention relates to a power supply with dimming control for high-power DC LED lamps. More particularly, the power supply is capable of adjusting luminance (brightness) and power consumption (consumed watts) of a light-emitting unit in a conventional high-power DC LED lamp, and is applicable to dimming control of one or more sets of such high-power DC LED units.
2. Description of Related Art
Referring to FIG. 1, FIG. 4, FIG. 6 and FIG. 8, in the case of average halogen lamps and tungsten filament lamps (incandescent lamps), the dimming control is achieved by changing the voltage or current of a transformer 1 in the lamp. However, to a lamp with a high-power DC LED unit 41, by changing the voltage or current at the input end of its driver 2 is not effective to get significant dimming effects (only a variation about 10%-20%), and doing so can bring additional burdens to the power supply of the high-power DC LED lamp, leading to decreased stability and service life of the lamp. This is because the driver 2 typically provided in such a high-power DC LED lamp offsets the change of the voltage or current made at the input end of the driver 2, so the conventional means for dimming control by changing the voltage or current is inadequate for the light-emitting unit of a high-power DC LED lamp.
In the current technology, there is no way to perform dimming control of the high-power DC LED unit 41 of a high-power DC LED lamp by adjusting a transformer, an adapter/power supply 1, a driver 2 in the burner/bulb or a conventional dimmer.
Therefore, the existing high-power DC LED lamp 4 fails to have dimming control and can be only operated between “on” and “off” and the lack of dimming control weakens the practicability of the existing device.